Checklist and Nomenclatural Authority File of the Scarabaeoidea of the Nearctic Realm including Canada, the continental United States, and the northern Mexican states of Baja California, Baja California Sur, Chihuahua, Coahuila de Zaragoza, Durango, Nuevo Leon, Sinaloa, Sonora, Tamaulipas, and Zacatecas. Version 4 - released 22 April 2009 Andrew B. T. Smith Canadian Museum of Nature P.O. Box 3443, Station D Ottawa, ON, K1P 6P4 CANADA asmith@mus-nature.